[PATCH 2/8] ARM: Implement read/write for ownership in theARMv6 DMA cache ops

[Russell King - ARM Linux]

On Mon, May 17, 2010 at 02:26:38PM +0300, Ronen Shitrit wrote:
> > How can you say that the current line won't be evicted?
>
> [Ronen Shitrit] Since the only ldr I see around is the ldr to the next
> line and next line will go to different line on the cache...

I think you mean different index, and yes, you're right about that.

However, I still feel that your solution is unsafe as long as
speculative prefetch is enabled; the assumption with speculative
prefetch from an architectural point of view is to assume that
the CPU has infinite prefetching.

The fact that we have non-ARM ARMv6 CPUs which do prefetch in ways
we don't know about means that we can't assume that ARMv6 CPUs
aren't going to have aggressive prefetching.